As the integration of a semiconductor device has become high, the width of a source/drain region and a gate electrode of a MOS transistor has been reduced. Therefore, the sheet resistance of the source/drain region and the gate electrode has become high, causing the operation of the device to become deteriorated.
Accordingly, a metal silicide film of low resistance materials is formed on the gate and the region implanted with an impurity, such as the source/drain region, in a semiconductor manufacturing process to lower the sheet resistance. Such silicide materials mainly use rare earth metals that react to silicon. For example, common silicides include tungsten silicide (WSi2), titanium suicide (TiSi2), and cobalt silicide (CoSi2).